Sealant is an important component of the modern car. It must be applied accurately if it is to accomplish its intended function of sealing cracks against moisture, fumes and sound. Also, accurate application assures good aesthetic appearance, avoids intrusion into unacceptable locations and minimizes the amount of sealant required per car to reduce cost.
Robotic application of sealant requires machine vision to gauge the as built seam locations so that the sealant bead can be adaptively applied. The sealant stream must be accurately aimed at the seam by the robot to form a bead on the seam. Often there is inadequate room to maneuver the robot wrist to achieve the desired sealant stream direction. Accordingly, a final directional correction by the applicator tool is desirable. Then the bead should be spread to provide an even coating in the immediate area.
Mechanical spreading of sealant is associated with the problems of maintaining a clean tool, not dripping, and contour following. A far better method of sealant spreading involves the use of controlled air streams to move the bead material after being applied to the surface and to flatten the material to the desired even coverage. The major drawbacks of mechanical tool spreading are thus avoided, albeit by the introduction of an air stream control problem.
Singular air stream spreading does not appear to be a viable approach. As a result, multiple air stream control is required to properly move and spread sealant bead material, once the material has been applied to the surface. This necessarily increases the complexity of this methodology and any simplification can greatly benefit the process.